Infertility affects approximately 16% of couples in the United States. Roughly one third of infertility is caused by male disorders, one third by female disorders, and one third by combined male and female disorders. The couple-based definition of infertility, combined with possible individual-level reproductive disorders, highlights the importance of including both partners in any study assessing modifiable factors and reproductive success. While urological and/or gynecological disorders are the primary underlying causes for infertility, diet and other modifiable lifestyle and psychosocial factors in both men and women can potentially mitigate or exacerbate fertility problems. Effects of lifestyle and psychosocial factors (here meant to describe dietary and supplement intake, physical activity, stress, depression, anxiety, weight, sleep patterns, smoking, alcohol, caffeine consumption, sexual activity, and intimate partner violence) on ovulation, conception, implantation, and embryonic and fetal development remain largely unexplored, but offer the potential for low-cost strategies to improve fertility. The goal of the proposed study is to evaluate the impacts of modifiable lifestyle factors on fertility in the context of a couple-based approach across a spectrum of fertility and treatment by inviting female partners of participants in the Folic Acid and Zinc Supplementation Trial (FAZST) to participate in the Impact of Diet, Exercise And Lifestyle on Fertility (IDEAL Fertility) Study. The IDEAL Fertility Study includes detailed follow-up (both questionnaires and biospecimen collection) of the female partners of men enrolled in the FAZST trial. Specifically, participants will complete an online daily journal regarding lifestyle factors, as well as visits during fertility treatment and throughout pregnancy for women who become pregnant during the study. The project finished recruiting in December 2017 and follow-up is continuing through 2018, with initial data analysis in 2019.